The nation's best data network is about to get much clearer voice calls. Verizon Wireless said it's about to launch voice-over-LTE, or VoLTE, with "HD Voice" nationwide on a range of existing smartphones. "It's the first major change in voice quality in a decade," Verizon spokeswoman Debi Lewis said.VoLTE amps up call quality by switching from an older, 8kbps codec to a 13kbps codec that also uses more modern compression methods. I made VoLTE and non-VoLTE calls side by side on an LG G2 phone. Like with other HD Voice implementations, sibilants sounded sharper. It was easier to tell similar sounds like "emm" and "enn" apart, and voices were more clearly differentiated from background noise.This isn't the first time I've heard Verizon VoLTE calling, and Verizon isn't the first HD voice carrier. Verizon demoed VoLTE all the way back in 2011, promising a 2012 rollout. The company decided it wanted its nationwide LTE network to be "substantially complete" before launching the service, Verizon's vice president for network technology Mike Haberman said."We have over 53 million subscribers on LTE at this point, 76 percent of our usage is on 4G [LTE], and we've deployed XLTE in greater than 350 markets across the country," Haberman said.Verizon demonstrated VoLTE on Android-powered smartphones, and the Windows Phone 8.1 Update 1 operating system supports VoLTE. While no iPhone supports VoLTE, it's widely rumored to be a feature in the upcoming iPhone 6.Not The First, But The First NationwideAll three other major carriers beat Verizon to the HD Voice post, but with different approaches. T-Mobile implemented its HD Voice over a 3G GSM network. That can't be done on a CDMA network like the one Verizon uses without a proprietary Qualcomm technology called 1x-Advanced, which Sprint is using. Verizon's trying to move traffic away from its older networks and onto LTE, so 1x-Advanced wouldn't be appropriate for its approach.AT&T is doing a city-by-city VoLTE/HD Voice rollout right now. T-Mobile is also rolling out VoLTE city by city, and it's using an even higher-quality 24kbps codec. Haberman said there's "no noticeable difference" between 13kbps and 24kbps. With all of these different kinds of VoLTE, interoperability is an issue. Right now in the U.S., you can only make HD calls between HD phones on the same carrier. Verizon is "in lab work" to enable HD calling with "other carriers" but "not Sprint" because Sprint isn't using global standards, Haberman said. "It's something that most likely will happen in the 2015 timeframe," he said.

VoLTE has much bigger implications for Verizon's network than just improving voice calls. It's necessary so Verizon can re-use, or "refarm" older spectrum for more LTE capacity, rather than use it for the much older and less data-efficient CDMA system. Verizon said in 2013 that it's going to start moving 1900MHz spectrum to LTE in 2015. That said, Verizon has said the CDMA system will hang around in some form until 2021 to support enterprise machine-to-machine clients.

Video Calling, TooVerizon's VoLTE also enables video calling, something we've been seeing carriers try since 2005. By and large, carrier video calling has been replaced by Skype and FaceTime, but Verizon will try to revitalize the field by making it part of your default phone dialer. You'll be charged data rates to make video calls, probably 6-8MB/minute, Haberman said. However, you'll only be able to call other Verizon VoLTE phones, as compared to third-party solutions which work across carriers.I briefly tried a video call; it looked a little soft, and I'd eyeball it at 15-20 frames per second. It wasn't HD, that's for sure. But these systems tend to change their resolution and frame rate based on network conditions, and Verizon didn't give the spec.More rich communication features will come in the future, like instant messaging and file transfer, Haberman said. And all VoLTE phones will have simultaneous voice and data capabilities."Think of VoLTE as a platform," he said.VoLTE will be an optional feature. It won't come turned on by default; you'll have to either turn it on with a switch in the phone's settings, or ask a salesperson to do it for you. That's because LTE and the older 3G network have slightly different coverage areas, and calls can't hand off between them - if you start a call on LTE and you drop to 3G, you drop your call. So for now, people who want to stay in 3G voice calling mode can stay there.Verizon wouldn't give an exact date for when the rollout would come except that it will have a specific date, within a few weeks. The service will not cost extra. Keep your eyes out.

About the Author

PCMag.com's lead mobile analyst, Sascha Segan, has reviewed hundreds of smartphones, tablets and other gadgets in more than 13 years with PCMag. He's the head of our Fastest Mobile Networks project, hosts our One Cool Thing daily Web show, and writes opinions on tech and society.
Segan is also a multiple award-winning travel writer. Other than ... See Full Bio

Get Our Best Stories!

This newsletter may contain advertising, deals, or affiliate links. Subscribing to a newsletter indicates your consent to our Terms of Use and Privacy Policy. You may unsubscribe from the newsletters at any time.